Labeling machines are used in industry to continuously apply labels at a high output onto continuously supplied articles, containers or packs of containers, respectively. The containers may be glass bottles, plastic bottles, in particular PET bottles, cans or can-like containers or the like, which are filled with liquid or solid food, medical or cosmetic products, hygienic products or the like. Here, the labeling machines in general comprise an often modularly designed labeling unit.
Such labeling units for labeling machines, in particular also for rotary-type labeling machines, for labeling bottles or similar containers with labels, in particular also those made of paper, using cold glue are known in prior art. Such units basically comprise at least one pallet or glue segment support that can be rotationally driven about a vertical unit axis, also referred to as pallet carousel, where a plurality of label pallets or glue segments forming at least one label receipt or label locating surface are provided. The pallets or glue segments are each embodied to be controlled to pivot about one separate swiveling axis. During labeling, the pallets or glue segments may be moved, with each circulation of the glue segment support, first past a gluing station to generate a glue application on its label locating surface, and subsequently past a label dispensing station where one label each is adopted which then adheres with its back to a label locating surface provided with the glue application and is thereby simultaneously provided with glue at its back. By means of a gripper cylinder, the labels provided with glue are each transferred to the containers moved past the labeling unit. As an alternative, the pallets, which may in particular be embodied as vacuum pallets, may be first moved past the label dispensing station to pick up a label with the image side facing the label locating surface. Subsequently, the label is taken along and guided past a gluing station with the glued side, whereby the back of the label is provided with glue. In this case, the above-mentioned gripper cylinder is omitted and the labels may be directly applied to the containers moved past the pallet carousel with their glued back.
The glue application onto the pallets or backs of the labels may be effected via a rotationally driven glue roller of which the circular cylindrical surface area is provided with a glue film by means of a glue application strip, or via a glue printer. A labeling unit having a glue printer is known, for example, from DE 10 2015 212 140. By means of individually controlled nozzles of the glue printer, the supplied glue, for example cold glue, is applied onto the pallets or labels, respectively, in a well-defined glue pattern by the ink-jet printing method.
Independent of whether a glue roller or a glue printer is employed, a continuous glue supply of the gluing station or the labeling unit is required. To this end, a glue supply device for the labeling unit is in general provided which delivers glue from a storage tank to the gluing station. In case of a glue printer, moreover a delivery at a constant glue pressure is required to guarantee a uniform glue pattern.
In the glue supply devices known from prior art, a glue container standing on the floor is generally used from which glue is pumped via hose pipes to the gluing station by means of a reciprocating pump, for example a chop check pump that is fixed to a lid of the glue container. Excessive glue may be transported back into the glue container via correspondingly disposed hose pipes. During the changing of the storage tank for the glue, however, the production is usually interrupted, and the glue pressure varies as the glue pump first must be removed to be subsequently inserted into a new, full storage tank. In the process, operators must move sometimes considerable masses because filled glue containers for cold glue often have a weight of 30 kg or more to keep the number of production interruptions as low as possible. Apart from the high weight for the operator, the contaminations of the glue occurring during the glue container replacement as well as moisture losses during the glue container replacement and during the operation of conventional labeling units with a glue roller pose a problem concerning the quality of the processed glue as its durability is often limited, as in the case of cold glue. Finally, the glue delivery by means of a reciprocating pump is inevitably subjected to pressure variations which render an efficient glue application by means of a glue printer difficult.
The object underlying the present disclosure is therefore to provide a glue supply device for a labeling unit, in particular a labeling unit with a glue printer, which permits a supply of glue to a gluing station at a constant pressure with as little interruptions as possible. In general, the object underlying the present disclosure is to increase the productivity and quality of a labeling unit. Moreover, the ergonomics of the operation of the glue supply device is to be improved.
The above-mentioned objects are achieved by a glue supply device for a labeling unit with a glue printer, comprising a storage tank for glue, in particular low-viscosity cold glue, a supply line for supplying glue from the storage tank to the glue printer, a continuously delivering glue pump embodied to deliver glue from the storage tank into the supply line, and a hydropneumatic reservoir for the glue, the hydropneumatic reservoir being disposed at the supply line upstream of the glue printer. The hydropneumatic reservoir may in particular be embodied to smooth pressure variations during the glue delivery to the glue printer.
The glue may be hot glue, UV glue, cold glue or another adhesive. In particular, viscous cold glues, such as casein glue or dextrin gum, for example, may be employed. As an alternative, dispersion glues may be used. The glue supply device according to the present disclosure may be used for low-viscosity glue, glue having a viscosity between 600 and 80000 mPas, and for casein or dispersion glue having an optimal processing temperature of 18° C. to 40° C. According to a special development, the glue supply device may be in particular employed in combination with a glue printer for low-viscosity cold glues. The viscosity of the used cold glues is here between 3 and 300 mPas, optionally within a range of 10 to 100 mPas.
Possible glue printers are described, for example, in the applicant's patent publication DE 10 2015 212 198, so that a detailed description may be omitted herein. It is only noted that the glue printer may have one or several controllable glue nozzles by means of which the glue is injected onto the glue application surface in drops or as a continuous jet under pressure. By purposefully controlling individual glue nozzles, a desired glue pattern may be created on the glue application surface. The glue printer may apply the glue pattern onto the glue application surface in particular according to the ink-jet printing method. Both an application with a continuous jet and one according to the DoD principle (Drop on Demand) are possible.
The storage tank for the glue may have a sufficient volume to permit the glue supply for a sufficiently long period. For example, the storage tank may have a glue volume of at least 20 l, optionally of at least 40 l, and of maximally 120 l. Depending on the glue pattern and the throughput of labels, the latter volume lasts for an operation of the labeling unit of about 8 to 24 hours.
The storage tank may have a level indicator. For example, a visual level indicator, in particular in the form of a viewing glass or a filling level pipe, may be provided. As an alternative or in addition, one or several filling level sensors may be provided and determine the filling level, for example via ultrasonic sound, and transmit it to the open-loop and/or closed-loop control unit described hereinafter. The filling level may be read out at a touch screen.
The supply line may be arranged such that it connects an outlet of the glue pump or a pipe piece connected with the glue pump with the glue printer. Here, the supply line may consist of a plurality of sections between which and/or at which further devices, as those described more in detail below are disposed. In particular, at least one section of the supply line may have an elastic design to permit, for example, a relative motion between the glue supply device and the glue printer or the labeling unit. In addition to the supply line, the glue supply device may also comprise a return line, in particular in case of a completely closed system, by means of which excessive glue may be conducted from the gluing station, in particular from the glue printer, back to the storage tank.
The supply line and/or the return line may be provided, in particular if hot glue is used, with a heating device which may be integrated, for example in the form of a heating wire, in the respective conduit, or which may be wound about an inner tube of the conduit. A number of alternative heating devices are conceivable, for example by means of channels through which hot water is flowing in or around the conduit. The heating device may in particular be controllable by a closed-loop control and be connected with an open-loop and/or closed-loop control unit of the glue supply device to which the glue temperature prevailing in the conduit is transmitted from a temperature sensor disposed in or at the glue conduit. The open-loop and/or closed-loop control unit may be a processor unit, in particular a stored program control (SPC). The open-loop and/or closed-loop control unit may be embodied to control the heating device as a function of the transmitted glue temperatures such that the glue is conducted through the respective conduit at an optimal processing temperature, for example between 20° C. and 40° C., optionally between 25° C. and 35° C. The desired glue temperature may here be entered by an operator, for example via a touch screen of the open-loop and/or closed-loop control unit, or be read out, as a function of the glue type used, from a storage unit of the open-loop and/or closed-loop control unit in the sense of a type management.
According to the present disclosure, the glue supply device comprises a continuously delivering glue pump by means of which glue is continuously delivered from the storage tank via the supply line to the glue printer. In contrast to the reciprocating pump mentioned above, the glue pump is a continuously delivering pump. In this manner, the pressure variations in connection with the operation of the glue pump are reduced in the supply line and at the glue printer.
For example, the glue pump may be embodied as a gear pump, in particular as an external gear pump. With a gear pump, in particular low-viscosity glue may be continuously delivered. The pump may furthermore be controllable, for example by a controllable servomotor being connected to the above-mentioned open-loop and/or closed-loop control unit. To this end, the glue supply device thus has a closed-loop or an open-loop control unit. The latter may comprise, as mentioned, a touch screen as an input and reproduction unit. Moreover, a common open-loop and/or closed-loop control unit for the glue supply device and the labeling unit may be provided.
The glue supply device may furthermore comprise a pressure gauge device, for example a pressure sensor, which are disposed directly upstream of or at the glue printer and are embodied to determine the glue pressure in the supply line upstream of the glue printer. Here, an arrangement directly upstream of the glue printer is to be understood such that the pressure sensor is arranged at a distance of less than 20 cm, optionally less than 10 cm, from the glue printer at the supply line. The determined glue pressure is transmitted from the pressure gauge device to the open-loop and/or closed-loop control unit by wires or wirelessly as a signal which in turn controls the delivery rate of the glue pump as a function of the glue pressure. Here, the delivery rate may in particular be controlled by closed-loop control such that at the glue printer, a desired glue pressure prevails that in general depends on the viscosity and which may be stored in the open-loop and/or closed-loop control unit, for example in the form of a type management, or which may be entered by an operator via the touch screen.
The open-loop and/or closed-loop control unit may consider further parameters for the control of the glue pump or the servomotor driving the glue pump, for example the above-mentioned temperature that has an influence on the viscosity of the glue. Moreover, a flow meter device may be arranged at or in the supply line and be embodied to determine the flow rate of glue through the supply line. The flow meter device may be embodied, for example, as a magnetic-inductive flow meter or as an ultrasonic flow meter. The measured flow rate may be taken into consideration by the open-loop and/or closed-loop control unit in the pump control process. Moreover, the glue type and/or the viscosity of the glue may be taken into consideration by the open-loop and/or closed-loop control unit. The open-loop and/or closed-loop control unit is thus embodied to control the glue pump as a function of the determined glue pressure, and optionally as a function of parameters such as the flow rate, temperature, viscosity and the type of glue.
According to the present disclosure, the glue supply device furthermore comprises a hydropneumatic reservoir for the glue which is arranged at the supply line upstream of the glue printer. The hydropneumatic reservoir may be embodied to smooth pressure variations during the glue delivery to the glue printer. Hydropneumatic reservoirs are well-known in prior art. In a closed container connected with a conduit via a hydraulic supply point, a gas space is separated from a liquid space by a movable and/or expandable separating element in a gas-tight manner. Gas, for example nitrogen or an inert gas, is introduced into the gas space via a filling valve in a controlled atmosphere at a desired pressure. Said pressure in particular corresponds, in the present application, to the desired glue pressure. The liquid space is filled with the liquid via a fluid connection with a conduit through which the liquid to be controlled with respect to pressure variations flows. In the present disclosure, the liquid space of the hydropneumatic reservoir is thus fluidically connected to the supply line of the glue supply device, so that the liquid space will fill with glue. The amount of gas in the gas space is here adapted such that during the operation of the pump, the desired pressure prevails. If the glue pressure differs from the desired pressure, the gas will be compressed or relieved in the gas space, depending on whether the glue pressure is above the desired pressure or below it, by moving or expanding the separating element. The compressibility of the gas thus attenuates the pressure variations of the glue in the supply line. The gas present in the gas space thus acts as a gas padding.
In other words, the hydropneumatic reservoir acts as a compensation tank that causes hydraulic decoupling between the supply line and the glue printer which stabilizes the glue pressure. To cause an effective hydraulic decoupling, the hydropneumatic reservoir may be arranged at a small distance to the glue printer. For example, a length of the supply line arranged between the junction of the hydropneumatic reservoir with the supply line and the glue printer may be less than 1 m, optionally less than 0.25 m. Due to the small distance to the glue printer, the disturbing influence of possible viscosity-dependent flow resistances is kept as low as possible.
The hydropneumatic reservoir may in particular be a membrane reservoir where the gas space is separated from the liquid space by a flexible membrane. As an alternative, the hydropneumatic reservoir may be a bladder reservoir with a flexible bladder as a separating element between the gas space and the liquid space, or a bellows reservoir with bellows as a separating element between the gas space and the liquid space. Finally, the hydropneumatic reservoir may also be embodied as a piston reservoir with a freely moving piston as a separating element between the gas space and the liquid space. The respective separating elements may in particular comprise corresponding sealing devices for separating the gas and the liquid spaces in a gastight manner. Equally, a spring or metal bellows reservoir is conceivable where a pressure spring is used instead of gas. Such reservoirs are maintenance-free.
The described glue supply device thus permits to continuously deliver glue with an approximately constant glue pressure from a storage tank to a glue printer. Due to the constant glue pressure, a well-defined glue pattern results on the one hand. On the other hand, the required amount of glue may be exactly controlled, so that both a sufficient glue application may be ensured and an excessive return of glue may be avoided. With precise control, one may thus possibly completely do without a return line for glue.
To apply glue by means of a glue printer, a working pressure of at least 15 bar, optionally of at least 30 bar, and up to 60 bar, may be required. The above described hydropneumatic reservoir thus also increases the safety of the glue supply device since it moderates undesired pressure peaks which could damage the glue nozzles of the glue printer or the supply line. To this end, the hydropneumatic reservoir may be embodied, for example, with a volume of the liquid space within a range of 0.1 l to 1 l.
Additionally, the glue supply device may comprise a safety valve at the supply line which is embodied to open an outlet when a limit pressure in the supply line is exceeded. The outlet may be connected with the exterior or, via a return line, with the storage tank. The safety valve thus acts as a pressure controller or a pressure control device. It may be arranged, for example, between the glue pump and the hydropneumatic reservoir. The safety valve may have an adjusting range for the limit pressure of 25 bar to 60 bar.
The glue supply device may furthermore comprise a retention device which is embodied to fix the glue pump to the labeling unit in a height adjustable manner. In particular, the retention device may be fixedly connected to the labeling unit or be embodied as a part thereof. By means of the retention device, the glue pump or its suction pipe may be lowered into the glue in the storage tank either manually or automatically via a linear servomotor. To change the storage tank, the glue pump may be driven out of the storage tank by means of the retention device.
This is particularly easy if the retention device comprise a telescopic rail and a cylinder with a gas pressure spring for the height adjustment of the glue pump. The gas pressure spring here facilitates the vertical movement of the glue pump. The term “vertical” is to be understood here and below with respect to a floor space of the labeling machine, for example with respect to the floor of the factory building.
According to a further development, the storage tank may be embodied to be exchangeable, in particular as a mobile module, wherein the glue supply device furthermore comprises mechanical receiving device, in particular a coupling plate, for coupling the storage tank to the labeling unit. Furthermore, the storage tank may be exchangeably arranged on a mobile module, for example a pack carriage. According to this development, the respectively employed storage tank is thus not fixedly connected, but via the receiving device releasably connected to the labeling unit. The receiving device may only serve as a positioning aid or comprise a mounting for the storage tank. The latter permits to move the storage tank along if the labeling unit must be lifted vertically, for example for attaching labels to higher containers.
To change the storage tank, the glue pump may first be driven out of the emptied storage tank by means of the height adjustable retention device manually or automatically, where the storage tank may then be easily removed manually. Subsequently, a new filled storage tank may be rolled to the labeling unit, for example by means of a pack carriage. The pack carriage can to this end have rollers and a guide rod which moreover fulfils, together with a mounting of the pack carriage for storage tanks, a lever function by means of which the full storage tanks may be received with a low expenditure of force and loaded onto the pack carriage. At the labeling unit, the new storage tank is inserted into the receiving device, for example with the aid of the lever function of the pack carriage. The pack carriage may be subsequently removed or remain at the labeling unit. In the described development, the operator thus neither has to lift the storage tank nor carry it. Thus, the storage tank may be brought into the intended position without any major expenditure of force and by means of the coupling plate. Subsequently, the glue pump is again lowered into the glue by the retention device. The change of a storage tank may thus be done within one minute only, whereby a possible interruption of the production is considerably reduced. Moreover, the described development improves the ergonomics of the device.
According to an alternative development, the storage tank may be fixedly connected to the labeling unit, for example with a housing or frame of the labeling unit. In this case, the storage tank does not have to be exchanged but only refilled. To this end, in particular the glue pump does not have to be driven out of the storage tank. The storage tank may rather have a lid which may be at least partially opened. Through the opened lid, the storage tank may be filled as required. Refilling may be effected, for example, by means of canisters, optionally in a pack size of 5 l to 10 l. Due to the small pack size, no large loads must be moved by the operator. As an alternative, the storage tank may be refilled via a barrel pump or via a central glue supply manually or automatically via a corresponding pump control. The latter may be done depending on a detected filling level of the glue in the storage tank, for which the above-mentioned filling level sensors may be provided.
The refilling of the storage tank with glue may in particular be effected already before the complete emptying of the storage tank by the operation of the labeling unit, so that an interruption of production may be avoided. Since the storage tank is directly fixed to the labeling unit, it may be embodied with a sufficient storage volume, for example within a range of 40 l to 120 l, to permit a permanent operation of the labeling unit of several hours. If one assumes, for example, a label surface of 175 cm2 of which 60% are provided with glue, a glued surface of 105 cm2 results. With a glue consumption of 16 g per m2 of glued surface, thus approx. 170 g of glue are required for 1000 bottles. If the labeling machine has a machine output of 50,000 bottles per hour, about 8.5 kg of glue per hour are thus required. A storage volume of 120 l thus permits a permanent operation of about 14 hours.
Independent of the arrangement of the storage tank, the glue supply device may furthermore comprise an auxiliary tank, the auxiliary tank being connected with the glue pump such that during a change of the storage tank, glue is withdrawn from the auxiliary tank by means of the glue pump. This may be achieved, for example, by a suction pipe of the glue pump being connected with the auxiliary tank via a valve which may be opened during a change of the storage tank. Correspondingly, a further valve may be provided in a suction pipe by means of which the glue pump sucks glue out of the storage tank, while the further valve for changing the storage tank is closed. As an alternative, the glue pump may comprise a branched suction pipe at the branch of which a three-way valve determines whether glue is sucked out of the storage tank or the auxiliary tank.
According to a special development, the auxiliary tank may in particular surround the glue pump and have a valve element which is embodied to open the auxiliary tank when in contact with a bottom of the storage tank, and to close it otherwise. More in detail, the valve element includes a mechanical and/or magnetic device to this end which is actuated by mechanical contact of the auxiliary tank with the bottom of the storage tank such that the valve element may be moved to an opened position. In this case, glue may thus be delivered from the storage tank through the glue pump located in the auxiliary tank.
If the auxiliary tank is not in contact with the bottom of the storage tank, the valve element closes the auxiliary tank. In this case, the glue pump located in the auxiliary tank only delivers the glue located in the auxiliary tank. The volume of the auxiliary tank may be, for example, at least 0.3 l, optionally at least 1 l, to provide a sufficient amount of glue for the time required for changing the storage tank. Since the auxiliary tank surrounds the glue pump, it may in particular be connected to it mechanically, so that the auxiliary tank may be driven out of the storage tank together with the glue pump to change the storage tank.
The opening of the auxiliary tank which is closable by the valve element may in particular be located in the bottom of the auxiliary tank or in a lower region of the auxiliary tank. If the opening is located in the bottom, the glue located in the storage tank may be pumped out nearly completely. In addition to the opening which is closable by the valve element, the auxiliary tank may have one or more inlet openings for the glue. These may be in particular disposed at an upper side of the auxiliary tank, for example in a lid, to be closable by the valve or to be always open. The dimensions and the shape of the auxiliary tank and the relative position of the openings of the auxiliary tank may be selected such that the auxiliary tank is initially filled with glue from the storage tank via the inlet openings by lowering it into the filled storage tank which glue subsequently serves as a buffer during the change of the storage tank. If the auxiliary tank is driven out of the storage tank together with the glue pump for changing the storage tank, the contact with the bottom of the storage tank is released and the valve element closes the lower opening that serves as a suction opening for the glue pump in the storage tank. Then, glue is thus only delivered from the auxiliary tank, so that the storage tank may be easily changed.
According to a special development, the glue pump may be embodied to be movable relative to a bottom of the auxiliary tank. In particular, the glue pump may be designed such that in contact with the bottom of the auxiliary tank, it no longer delivers any glue from the auxiliary tank. This may be permitted, for example, by correspondingly arranging a glue inlet opening of the pump, i.e. the pump inlet, and providing a sealing ring that seals the pump inlet with respect to the interior of the auxiliary tank in contact with the bottom of the auxiliary tank.
According to a special development, the bottom of the auxiliary tank may have a bore, the bore forming, by lowering the glue pump, together with a corresponding glue inlet opening of the glue pump, a supply line for glue from the storage tank that is closable via the valve element. The bore is thus in particular arranged opposite to the glue inlet opening of the glue pump. By lowering the glue pump, the glue inlet opening is brought into contact with the upper opening of the bore thus forming a supply line for glue. Via the lower opening of the bore or via a glue channel connecting the bore with the exterior of the auxiliary tank in the bottom of the auxiliary tank, glue from the storage tank may then be sucked in. The supply line formed by the bore, the glue inlet opening and the glue channel thus connects a delivery space of the glue pump, for example the space where the gears of a gear pump are arranged, with the exterior of the auxiliary tank or the storage volume of the storage tank. To seal the formed supply line with respect to the interior of the auxiliary tank, the above-mentioned sealing ring may be provided at the bottom of the glue pump.
By providing the described auxiliary tank, the period during which the storage tank is being changed may be easily bridged. The auxiliary tank thus ensures a glue supply by the glue supply device according to the present disclosure without any interruptions. The prevention of any interruption of the glue supply moreover permits a constant glue pressure at the glue printer since the starting of any glue pump after an interruption of production always involves a relatively slow increase of the glue pressure to the working pressure. In combination with the attenuation of delivery-dependent pressure variations by the hydropneumatic reservoir, with the described glue supply device, a constant glue pressure may thus be provided without any interruptions, which in particular renders the use of a glue printer economically interesting.
The present disclosure also provides a labeling unit for applying labels onto containers, comprising a glue supply device according to the above-described developments. Moreover, the labeling unit according to the present disclosure comprises a pallet carousel with a plurality of pallets driven to circulate about an axis of rotation and a glue printer arranged in the periphery of the pallet carousel and having a plurality of glue nozzles controllable individually or in groups. Pallet carousels are well-known in prior art so that a detailed description is omitted here. It should be only noted that the pallets may be embodied as vacuum pallets connected with a vacuum device for generating a vacuum at the pallet. In this case, the pallets may be guided, upstream of the glue printer, past a label provision unit, for example a label box, from which they receive the labels with the image side facing the label locating surface. The backs of the labels are subsequently provided with a desired glue pattern by means of the glue printer. As an alternative, glue application surfaces of the pallets may be provided with glue by the glue printer. In this case, the label provision unit is disposed downstream of the glue printer, and the labels are here transferred to the glued pallets with their backs. Subsequently, the labels may be picked up by a gripper cylinder of the labeling unit and transferred to the containers. A plurality of variations of the labeling unit is conceivable and combinable with the glue supply devices according to the present disclosure. For example, instead of a label box, a label cutting device for cutting a continuously supplied label tape may be provided. The glue printer may be operated, as already described above, according to the ink-jet printing method and be provided with a plurality of glue nozzles controllable individually or in groups. The control may be effected via the above described open-loop and/or closed-loop control unit.
The above-mentioned objects are also achieved by the use of the above-described glue supply device where the storage tank is designed to be exchangeable, in particular as a mobile module, wherein, for changing the storage tank, the glue pump is driven out of the storage tank by means of the above-described retention device, and wherein a filled storage tank is approached to the glue supply device by means of a pack carriage.
If the remaining glue stock in the storage tank is insufficient, the glue pump may be driven out of the storage tank without major expenditure of force to such an extent that the empty storage tank may be easily removed manually, as described more in detail above. Subsequently, a filled storage tank is driven towards the glue supply device and there docked, for example, to a coupling plate. The glue pump is subsequently driven into the filled storage tank by means of the retention device, wherein in particular, as described more in detail hereinafter, the auxiliary tank may be brought into contact with the bottom of the storage tank. Thereby, a valve element of the auxiliary tank, via which glue may be sucked from the storage tank, is opened. Said valve element is automatically closed when the glue pump is driven out of the storage tank, for example as described below, by correspondingly arranged magnets or a readjusting spring, so that during the changing of the storage tank, glue may be pumped from the auxiliary tank. The latter thus serves as a glue buffer for the changing process. The use according to the present disclosure thus permits a supply with glue without any interruptions.
The above-mentioned objects are finally also achieved by the use of a glue supply device whose storage tank is permanently fixed to the labeling unit, with a glue having a viscosity within a range of 3 to 300 mPas, optionally within a range of 10 to 100 mPas, wherein the storage tank is refilled through the open lid by means of canisters. When a low-viscosity glue is used, i.e. with a viscosity within the indicated ranges, the storage tank may also be comfortably filled via a lid that can be opened. This may be done by the operator by means of a canister, wherein the pack size for the canister may be within a range of 5 l to 10 l. In this manner, the operator does not have to move large loads. The refilling of the storage tank may be effected during operation, so that the storage tank may be effectively prevented from running empty. In this use of the glue supply device, too, a glue supply free from interruptions may be achieved.